Toolholder



W. L. SITTON Aug. 22, 1950 TOOLHOLDER Filed April 16, 1946 4 IN VEN TOR. W/'///'a/77 L. S/Liofl ATTU RNEYS Patented Aug. 22, 1950 UNITED STATES hATENT OFFICE This invention relates to a new and useful improvements in tool holders adapted especially for lathes, sharpers and similar metal workin machines.

Bits, cutters and similar tools are customarily supported by holders. These tool holders are inserted between the jaws of the tool post of the lathe to which they are secured by means of a set screw or the like. As the lathe revolves a work piece the tool bears against the work piece and works it in any manner desired.

Since great force is necessarily involved in working revolving metal, a rigid support for the tool is of great importance. This importance is even greater when hard steels are being worked.

Most tool holders in current use have the disadvantage that they are constructed either for left hand work only, for right hand work only or for straight work only.

The additional tool holders especially designed for reversible right or left hand work have the disadvantage that the tool enters the tool holder at a horizontal angle thus making the distance between the tool holder and the work necessarily greater and materially reducing the rigidity of the tool.

This invention provides a tool holder which may be used alternately for either right hand, left hand or straight work.

The tool holder of this invention has a straight shank portion with a bent shank portion at an angle thereto. As a result, in right and left hand work in which the tool is ordinarily held at an angle to the tool holder, the tool is in this in- Vention held in alignment with the tool holder and the necessary angle is provided by a bend in the tool holder itself which is of stronger and heavier construction than the tool. The tool holder of this invention is therefore more ridged than those in current use.

The invention will be better understood from the following detailed description thereof with reference to the accompanying drawings in which:

Figure 1 is a top plan view of the tool holder and set screw sleeve with the tool being held in a position for straight work;

Figure 2 is a side elevation of the tool holder partly in section and showing the manner in which the tool is mounted for straight work as well as the angles of inclination of the channels for the reception of the tool for right and left hand work and also shows the set screw passageways;

Figure 3 is a top plan view of the tool holder 1 Claim. 2S-96) with the tool held in a position for right hand work in a channel of the bent section thereof;

and

Fig. 4 is another top plan view showing the tool holder and tool in a position for left hand work.

The tool holder of this invention has a straight shank portion ill with a bent shank portion ll attached at any desired obtuse angle to the straight shank portion l t.

The shank portions l0 and H are preferably constructed of heavy cold rolled steel to provide the required strength and rigidity.

A recess 22 is provided in the straight shank portion ill of a square shape in cross section for the reception in the recess l2 of a tool i3. The recess i2 is preferably sloped upwards toward its outer end to maintain the thrust on the tool It from the work piece as directly in alignment with the axis of the tool it as possible thereby minimizing the tendency of the'tool to shear.

A passageway M for the reception of set-screw l5 enters the straight shank portion l 9 preferably at a right angle to the tool recess E2.

The passageway M may be threaded, if desired, and the tool rigidly clamped by means of a conventional set screw. It is preferred, however, to employ a sleeve having a screw threaded opening I! in the top thereof since by the use of a sleeve the threads may be made larger and stronger without a weakening of the tool holder. lne sleeve it extends entirely around the tool holder, although it could be extended only a part way around. In no event, even though the tool holder be round in circumference, should the sleeve extend less than one-half way around the circumference of the tool holder.

The bent shank portion II has a right hand channel i8 and a left hand channel is extending there through for holding the tool E3 in either a right or a left hand cutting position respectively.

The tool channels 18 and i9 meet at 2% in an acute angle and each channel H3 or I9 is sloped upwards at its outer end 25 at times when the tool is used in right or left hand positions respectively.

The tool channels it and 49 as well as the tool recess l2 preferably extend entirely through the tool holder, whenever possible, to allow the use of tools of unlimited lengths. It will be seen, however, by reference to Figure 2 that the usual angles of slope for recess [2 would not allow the extension of recess l2 without a conflict with the end 2! of channel iii. For that reason, the

recess I 2 ends in a hole 22 extending through the sides of the tool holder.

Each tool channel l8 and [9 has a set screw passageway 23 extending thereto and meeting channels l8 and 9 at right angles. As discussed with respect to set screw passageway H, the passageways 20 may also be threaded but preferably the sleeve I6 is used.

ihe ends 24 and 25 of the tool holder are rounded to provide clearance for the tool 93 to be set as close as possible to the work piece (not shown).

The operation, should the tool holder be used for straight work the tool 13 is inserted into recess l2 and rigidly secured thereby set screw 15. In all positions the tool holder is held in the jaws of the tool post by its mid-section on the straight shank portion I0.

When it is desired to use the tool holder for right hand work the tool is inserted instead into channel l8 of the bent shank section H, the sleeve It is placed around the bent shank section II and the set screw inserted through passageway 23 and tightened. The tool holder is held by the tool post in the position shown in Figure 3 of the drawings for right hand work.

For left hand work the adjustments are substantially the same as for right hand work with the exception that the tool is inserted instead into channel l9 and the tool holder is held by the tool post in the position shown in Figure 3.

The foregoing description of the invention is for illustrative purposes only and it is understood that some modifications may be made in the invention within the scope and spirit of the appended claim.

Having thus fully described my invention, what I claim is:

A tool holder for lathe Work, comprising a straight shank portion having a bent shank portion attached at an upwardly inclined angle thereto, said bent shank portion having a channel therein for the reception of a tool and a passageway therein at an angle to said channel for the reception of means for holding said tool firmly in said channel, said bent shank portion also having a second tool channel therein positioned at an angle to said first mentioned tool channel, the forward end of the channels meeting at a common opening at the forward end of the bent portion and the channels inwardly of the common opening extending from each other at an acute angle and the opposite ends of said first and second mentioned channels extending entirely through said bent shank portion for the reception of a tool of unlimited length, said bent shank portion also having a, second passageway therein positioned at an angle to said second channel for the reception of means for holding said tool firmly in said second channel said tool holding means including a sleeve which extends around said tool holder and a set screw in said sleeve adapted to engage said tool.

WILLIAM L. SITTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 238,322 Allen Mar. 1, 1881 492,381 Armstrong Feb. 28, 1893 854,669 Reidy May 21, 1907 2,416,774 Rosenblatt Mar. 4, 1947 2,475,784 Grove July 12, 1949 FOREIGN PATENTS Number Country Date 2,835 Great Britain July 12, 1876 484,843 France Nov. 13, 1917 

